3-(Cyclopenten-1-yl)-benzyl-or 3-(cyclopenten-1-yl)-heteroarylmethyl-amine derivatives and use thereof as medicines for treating schizophrenia

ABSTRACT

The invention provides compounds of the formula: 
                         
wherein (a) is a single or double bond; W is CH, CH 2 , CHCH 3 , CCH 3 , C(CH 3 ) 2 , C(CH 2 ) 2  or C(CH 2 ) 3 , provided that when (a) is a double bond, then W is CH or CCH 3 , and when (a) is a single bond, then W is CH 2 , CHCH 3 , C(CH 3 ) 2 , C(CH 2 ) 2  or C(CH 2 ) 3 ; X is CH or N; and Y is H or F, and salts, hydrates, tautomers, pure enantiomers, and enantiomeric mixtures; and a method of treating schizophrenia comprising administering same.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national stage of International Appln. No.PCT/FR2003/003053, filed Oct. 16, 2003, which claims priority under 35U.S.C. §119 of French Patent Appln. No. 02/12854, filed Oct. 16, 2002,said applications being incorporated by reference herein in theirentireties and relied upon.

Schizophrenia is a serious and incapacitating mental disease whichaffects more than 50 million people worldwide (Sciences 2002, 296(5598),692–5). The mechanisms which underlie schizophrenic psychoses arecomplex. It appears however established that a dysfunction in thedopaminergic transmission is involved in their symptomatologies (Nature1988, 336, 783–87; Pharmacol. Rev. 2001, 53(1), 119–33). Indeed,antagonists of the central dopaminergic receptors, in particular of thereceptors of the D₂ subtype (e.g. haloperidol, chlorpromazine and thelike) constitute a conventional and clinically effective approach to thetreatment of schizophrenic psychoses, in particular of the so-calledpositive or productive symptoms (Nature 1976, 261, 717–19). Compoundspossessing such a mechanism of action nevertheless induce side effects,not correlated with the therapeutic action, such as parkinsonian typesymptoms (Pharmacotherapy 1996, 16, 160), tardive dyskinesia, endocrinedisorders and the like (Drug Metab. Dispos. 1997, 25(6), 675–84).

Another class of so-called atypical antipsychotic agents was introducedmore recently (ID 2002, 3(7), 1073–80). In terms of therapeuticadvantages, the advantage of these novel agents compared with theconventional agents lies in:

-   -   a lower propensity to causing side effects of a neurological        order, in particular extra-pyramidal effects (J. Clin.        Psychiatry 2000, 61(S3), 10–5);    -   an increased antideficiency activity (CNS Drugs 2002, 16(4),        249–61);    -   a greater efficacy in certain refractory forms of schizoprenia        (CNS Drugs 2002, 16(7), 473–84).

These atypical compounds (e.g. clozapine, risperidone, olanzapine andthe like) act in general both as dopaminergic and serotoninergicantagonists, in particular at the level of the 5-HT₂ type receptors(Psychopharmacol. Bull. 1989, 25, 390–92; Psychopharmacology 1993, 112,S40–S54). Each of these medicaments possesses nevertheless a differentaffinity profile not only at the level of the subtypes of dopaminergicand serotoninergic receptors, but also at the level of the muscarinic,adrenergic and histaminic receptors. Thus, an affinity profilecharacteristic of an “atypical” status does not appear to emerge.

It is evident, nevertheless, from several clinical studies (Br. Med. J.2000, 321, 1360–61 and 1371–76) that in general:

-   -   the atypical agents are no more effective than the so-called        conventional agents, at least from the point of view of the        positive (or productive) symptoms; the impact on the deficiency        (or negative) syndromes being more difficult to objectify in        human clinical medicine;    -   the atypical agents exhibit better neurological tolerance than        conventional agents, but induce moreover side effects which are        specific to them (e.g. weight gain, diabetes, sexual disorders,        hematological and/or cardiac toxicity and the like); some of        these side effects being as serious as the extrapyramidal        effects sometimes associated with treatments with conventional        agents (Br. Med. J. 2002, 325, 243–5).

Overall, the existing therapeutic approaches for the treatment ofschizophrenic psychoses are therefore not completely satisfactory (J.Med. Chem. 2001, 44(4) 477–501). The discovery of novel more effectiveand better tolerated treatments is therefore highly desirable.

It has been shown in animals that the 5-HT1_(A) antagonists are, interalia, capable of combating catelepsy (J. Neural Transm. 1991, 83(1–2),43–53; J. Pharmacol. Exp. Ther. 1993, 265(1), 207–17; Eur. J. Pharmacol.1998, 356, 189–92) and of attenuating the increase in the plasma levelof prolactin (J. Pharmacol. Exp. Ther. 1989, 249, 23641), induced by D₂antagonists. 5-HT1_(A) agonists also have in their capacity to increasethe release of dopamine and acetylcholine in the prefrontal cortex(Brain Res. 2002, 939, 34–42), properties which conventional agents donot possess and which are assumed to contribute to the antideficiencyactivity of the so-called “atypical” agents (J. Psychopharmacol. 2001,15(1) 37–46). Finally, the anxiolytic and antidepressant effects of the5-HT1_(A) agonists constitute an advantage during the treatment ofschizophrenic psychoses. The combination, in the same medicament, of anactivity of the D₂ receptor antagonist type and of the 5-HT1_(A) subtypereceptor agonist type is therefore, in theory, highly desirable since itwould confer both a broader activity spectrum (e.g. positive symptoms,antideficiency activity, antidepressant activity and the like) and abetter tolerance than conventional agents (e.g. extrapyramidal effects)and than most atypical agents. Given the potential therapeutic benefitrepresented by a D₂ antagonist and 5-HT1_(A) agonist combination,numerous compounds having such a profile are described in the literature(J. Pharmacol. Exp. Ther. 2000, 295(3), 853–61). There may be mentioned,by way of example, arylpiperazine derivatives (e.g., Bioorg. Med. Chem.Lett. 2001, 11, 2345–49; J. Med. Chem. 2001, 44, 186–97; Biorg. Med.Chem. Lett. 1999, 9, 1679–82; Pharmazie 2001, 56, 803–07; J. Med. Chem.1998, 41, 2010–18; Pharmazie, 1998, 53, 438–41; Arzneim-Forsch. 1997,47, 239–43; Med. Chem. Res. 1997, 7, 76–86; Pharmzie 1997, 52, 423–8; J.Med. Chem. 1994, 37, 99–104; DE 10043659; WO 0216354; WO 9811068; WO9703067; J. Med. Chem. 1992, 35, 552–58; J. Med. Chem. 1995, 38,1498–20; WO 9955672; U.S. Pat. No. 6,310,066; J. Med. Chem. 1998, 41,760–71 and WO 09711070; Bioorg. Med. Chem. Lett. 2001, 11, 2345–49; Drugof the Future 2001, 26, 128–32; Exp. Opin. Ther. Patents 1998, 8, 737–40and EP 900792; EP 770066; WO 9736893; WO 9711070 and J. Med. Chem. 1998,41, 760–71; WO 9818797; WO 0168063); aminotetralin derivatives (e.g.Bioorg, Med. Chem. Lett. 1999, 9, 1583–86; Biorg. Med. Chem. Lett. 1999,7, 1263–71 and 2541–48; Bioorg. Med. Chem. Lett. 1999, 7, 2541–48; J.Med. Chem. 1993, 36, 1053–68); benzodioxane derivatives (e.g., EP707007; WO 0172741; WO 9840386; WO 9829415; WO 9723485; WO 9507274 andJ. Med. Chem. 1999, 42, 3342–55; WO 9717343; EP 669331);aryloxyethylamine derivatives (e.g., WO 0198293; WO 9808817; U.S. Pat.No. 5,958,965; WO 9951576).

However, despite the abundance of compounds described as D₂ antagonistsand 5-HT1_(A) agonists, only one remains clinically available (i.e.nemonapride: RN 75272-39-8) and three are reported as being under activedevelopment in neuroleptic indication (PJB Publications Ltd. 2002) i.e.SSR-181507 (Sanofi-Synthelabo), bifeprunox and SLV-313 (Solvay). Thecontrast between the number of candidates and the number of compounds inclinical medicine illustrates, inter alia, the difficulties in obtainingadditional effects from the concomitant action of two distinct systemsby means of a single chemical entity. In this regard, the Applicant hasdiscovered that several compounds derived from(3-(cyclopenten-1-yl)-[benzyl or pyrid-3-ylmethyl])-(2-aryloxyethyl)amine selectively interact with the dopaminergic receptors of the D₂/D₃subtypes and the serotoninergic receptors of the 5-HT1_(A) subtype atthe level of which they behave as antagonists and agonists,respectively. As conventional agents, and unlike the so-called“atypical” compounds, the compounds of the invention have the advantage,in vivo, of effectively blocking the D₂ type receptors and therefore ofbeing potentially active in the treatment of the productive symptoms ofschizophrenia. However, unlike the conventional agents and certainatypical agents, the compounds of the invention do not cause catalepsyin animals even at doses much higher than the pharmacological doses. Theinduction of catalepsy in animals is known as being representative ofthe extrapyramidal effects which manifest themselves in humans. Theactivity profile of the compounds of the invention is therefore, in thisregard, quite remarkable. As such, the compounds of the invention aretherefore potentially useful for the treatment of schizophrenicpsychoses for which a great therapeutic need exists. The closest stateof the art is represented by the compounds described in patents JP05255302 and JP 05125024 of formula:

in which:

-   R1, R2, R5 and R6 may be a hydrogen atom or a simple alkyl group;-   R3 and R4 represent, inter alia, a hydrogen atom or a simple alkyl    group;-   m is between 1 and 5;-   n is between 1 and 4.

The compounds in question are claimed as being selective ligands of the5-HT1_(A) receptors which are useful for the treatment of disordersaffecting the central nervous system.

U.S. Pat. No. 6,121,307 and WO 9951575 claimN-[(aryloxy)ethyl]indoylalkylamines of formula:

in which

-   R1 may be a hydrogen atom;-   X and Y can form a heterocycle of the furanyl or dihydrofuranyl    type;-   n is between 2 and 5;-   as active agents at the level of the serotoninergic system, in    particular on the 5-HT1_(A) receptors, which are useful in the    treatment of depression.

The compounds of the invention therefore differ from the derivatives ofthe prior art both in their mechanism of action and in their chemicalformula. For example, the fragment [3-cyclopenten-1-ylbenzylamino] onlyappears in the derivatives of the4-(1-cyclopenten-1-yl)-2-[(dialkylamino)methyl]phenol type used ascomplexing agents (Izv. Vyssh. Uchebn. Zaved., Khim. Tekhnol. 1980,23(4), 406–11). The major benefit of the compounds of the inventiontherefore lies in their complementary action, or even in somesynergistic cases, at the level of the serotoninergic and dopaminergicsystems. Indeed, we show in vivo that the dose-effect curve (i.e.normalization of the stereotypisms which is due to the activation of thedopaminergic receptors) of certain compounds of the invention is movedto the right in the presence of the selective 5-HT1_(A) antagonistWAY-100635 (RN 162760-96-5). Conversely, these same products becomehighly cataleptigenic in the presence of WAY-100635. This synergy ofactivity, which is unexpected in the light of the results for thecompounds of the prior art claiming a similar, mixed mechanism of action(Psychopharmacol. 1999, 144(1), 20–29) opens novel therapeuticperspectives in human clinical medicine in a field for which theexisting medicaments are not totally satisfactory.

More specifically, the subject of the present invention is novelderivatives of the [(benzofuranyl-7-oxy)ethyl]-[(cyclopenten-1-yl)-{arylor heteroaryl}-methyl]amine type which, in the form of a base,corresponds to general formula (1):

in which:

-   -   (a) represents a single bond or a double bond;    -   W represents a CH, CH₂, CHCH₃, CCH₃ or C(CH₃)₂ group, a C(CH₂)₂        group (i.e. a carbon atom bearing two methylene groups linked        together so as to form a spiro-cyclopropane unit) or a C(CH₂)₃        group (i.e. a carbon atom bearing two methylene groups linked to        another methylene group so as to form a spiro-cyclobutane unit)        with the proviso, however, that when (a) is a double bond, then        W exclusively represents a CH or CCH₃ group, and that when (a)        is a single bond, then W exclusively represents a CH₂, CHCH₃,        C(CH₃)₂, C(CH₂)₂ or C(CH₂)₃ group;    -   X is a carbon atom bearing a hydrogen atom (CH) or a nitrogen        atom;    -   Y is a hydrogen atom or a fluorine atom;

their addition salts and optionally the hydrates of the addition saltswith pharmaceutically acceptable inorganic acids or organic acids andtheir tautomeric forms, the pure enantiomers and mixtures of racemic ornonracemic enantiomers.

Some compounds of the invention contain an asymmetric carbon atom intheir structure. Consequently, they exist in the form of enantiomers.The invention relates to both each pure enantiomer, that is to saycombined with less than 5% of the other enantiomer, and their mixture inany proportions. The compounds of the invention may therefore be used aspure enantiomers or racemic or nonracemic mixtures.

The invention finally extends to the process for preparing thederivatives of general formula (1). The derivatives of general formula(1) may be obtained by the process described in Scheme A.

Scheme A

The compound of formula (1) is prepared by a conventional reductiveamination reaction between the aldehyde of formula (2), in which X and Yhave the same meaning as above, and the primary amine of formula (3), inwhich (a) and W have the same meaning as above. The expression “aconventional reductive amination reaction” means that the aldehyde offormula (2) and the primary amine of formula (3) are reacted in anappropriate solvent and that the mixture of the reagents (2) and (3) isthen subjected to the reducing agent according to a method well known tothe organic chemist.

The compounds of formula (1) are purified according to one br moremethods chosen from crystallization and/or liquid phase chromatographytechniques. They may then be, if desired, salified by means of apharmaceutically acceptable acid.

The preparation of the aldehydes of formula (2) depends on the nature ofthe groups X and Y. Thus, the preparation of the aldehyde (2a) in whichX represents a carbon atom bearing a hydrogen atom (CH) and Y is ahydrogen atom is described in scheme B.

Scheme B

The ethyl 3-cyclopenten-1-ylbenzoate of formula (4a) is directlyobtained from ethyl 3-iodobenzoate and cyclopentene, which arecommercially available, by means of a Heck reaction catalyzed bytris(dibenzylideneacetone)dipalladium (RN 52409-22-0). The reduction ofthe ester functional group of the compound of formula (4a) by means of ahydride-donating agent such as, for example, lithium aluminum hydrideleads to the alcohol of formula (5a). The oxidation of the primaryalcohol functional group to the expected aldehyde of formula (2a) isthen carried out by means of manganese dioxide in chloroform in the hotstate.

The preparation of the aldehyde (2b) in which X represents a (CH) groupand Y represents a fluorine atom is described in Scheme C.

Scheme C

The ethyl 3-(2-oxocyclopentyl)benzoate of formula (7) is obtained byrearrangement (J. Org. Chem 1996, 61(5), 1877–79 and Synth. Commun.1990, 20(12), 1751–56) of the epoxide of formula (6), which is itselfprepared by epoxidation of the double bond of the intermediate (4a,Scheme B) by means of an organic peracid such as, for example,m-chloroperbenzoic acid. The conversion of the ketone functional groupof the compound of formula (7) to a gem-difluoro functional group,followed by the removal of HF in a basic medium (Tetrahedron 1990,46(12), 4255–60), gives the derivative of formula (4b). The reduction ofthe ester functional group of the compound (4b) to a primary alcohol,and then its oxidation according to a sequence similar to that describedabove (cf. Scheme B), leads to the expected aldehyde of formula (2b).

The preparation of the aldehyde (2c) in which X represents a nitrogenatom and Y is a hydrogen atom is described in Scheme D.

Scheme D

The addition of 1,4-bis(bromomagnesio)butane (RN 23708-47-6) to themethyl ester of 5-bromonicotinic acid (RN 29681-44-5), which is carriedout according to a protocol similar to that described in Eur. J. Med.Chem. 1991, 26, 563, leads to 1-(5-bromopyridin-3-yl)cyclopentanol offormula (8). A dehydration reaction gives the unsaturated derivative (9)which may then be converted to the expected aldehyde (2c) by applying amethod similar to that described in Tetrahedron Lett. 2002, 43, 4285–87.

The primary amines of formula (3), in which W and (a) are as definedabove, may be prepared according to a method similar to those describedin U.S. Pat. No. 6,121,307; WO 0058282 and WO 0032557 (Scheme E):

thus, the monoalkylation of a suitably substituted hydroxylatedderivative (10), by means of 1-bromo-2-chloroethane, which iscommercially available, leads to the ether of formula (11). The nitrogenatom is then introduced by substitution of the chlorine atom of compound(11) by means of an appropriate reagent such as for example sodium azideor potassium phthalimide. The primary amine functional group is thenreleased either by reducing the azido functional group or byhydrazinolysis of the phthalimido functional group to give thecorresponding primary amines (3).

The hydroxylated derivatives of formula (10), which are used as rawmaterials in the synthesis of the compounds of formula (11), areobtained in the following manner:

-   -   the compound (10a) in which W is a C(CH₃)₂ group and (a)        represents a single bond is commercially available (RN        1563-38-8);    -   the compound (10b) in which W is a CHCH₃ group and (a)        represents a single bond is described in U.S. Pat. No.        3,547,955; WO 8700840 and WO 9630367;    -   the compound (10c) in which W is a CH group and (a) represents a        double bond is prepared according to U.S. Pat. No. 6,121,307;    -   the compound (10d) in which W is a CCH₃ group and (a) represents        a double bond is prepared according to the method described in        Tetrahedron 1996, 52(28), 9499–9508;    -   the compound (10e) in which W is a CH₂ group and (a) represents        a single bond is prepared according to French patent filing No.:        01 03877;    -   the compound (10f) in which W is a C(CH₂)₂ group and (a)        represents a single bond is prepared according to the process        illustrated in Scheme F below.

Scheme F

The hydroxyl group of the compound of formula (12), EP 50957, is firstof all protected in the form of a silylated ether (in Scheme F, theabbreviation TBS means tert-butyldimethylsilyl). The ester functionalgroup of the compound of formula (13) may then be reduced to a primaryalcohol by means of a hydride-donating agent (J. Pharm. Pharmacol. 1999,51(4), 427–34). After converting the hydroxyl group of compound (14) toa chlorine atom, a reductive rearrangement reaction (Tetrahedron Lett.2001, 42, 939-41) makes it possible to obtain an exo-methylenederivative (16). A cyclopropanation reaction, which is carried outaccording to J. Org. Chem. 1992, 57(19), 5271–76, provides thespiro-propane compound (17) which is then deprotected to give theexpected compound (10f).

The subject of the invention is also the pharmaceutical compositionscontaining, as active ingredient, at least one of the derivatives ofgeneral formula (1) or one of its salts or hydrates of its salts incombination with one or more inert carriers or other pharmaceuticallyacceptable vehicles.

The pharmaceutical compositions according to the invention may be, byway of example, compounds which can be administered orally, nasally,subligually, rectally or parenterally. By way of example of compositionswhich can be administered orally, there may be mentioned tablets,gelatin capsules, granules, powders and oral solutions or suspensions.The formulations appropriate for the chosen form for administration areknown and described for example in: Remington, The Science and Practiceof Pharmacy, 19th edition, 1995, Mack Publishing Company.

The effective dose of a compound of the invention varies according tonumerous parameters such as for example the chosen route ofadministration, the weight, age, gender, state of progression of thepathology to be treated and the sensitivity of the individual to betreated. Consequently, the optimum dosage will have to be determinedaccording to the parameters which are judged to be relevant by thespecialist in the field. Although the effective doses of a compound ofthe invention can vary in large proportions, the daily doses could bebetween 0.001 mg and 100 mg per kg of bodyweight of the individual to betreated. A daily dose of a compound of the invention of between 0.010 mgand 50 mg per kg of bodyweight of the individual to be treated ishowever preferred.

The pharmaceutical compositions according to the invention are useful inthe treatment of schizophrenic psychoses.

EXAMPLES

The following examples illustrate the invention without however limitingits scope.

In the examples below:

-   (i) The progress of the reactions is monitored by thin-layer    chromatography (TLC) and consequently the reaction times are only    mentioned as a guide.-   (ii) The various crystalline forms can give different melting    points; the melting points reported in the present application are    those of the products prepared according to the method described and    are not corrected.-   (iii) The structure of the products obtained according to the    invention is confirmed by nuclear magnetic resonance (NMR) and    infrared (IR) spectra, and percentage analysis; the purity of the    final products is checked by TLC.-   (iv) The NMR spectra are recorded in the solvent indicated. The    chemical shifts (6) are expressed in part per million (ppm) relative    to the tetramethylsilane. The multiplicity of the signals is    indicated by: s, singlet; d, doublet; t, triplet; q, quadruplet; m,    multiplet; b, broad.-   (v) The various symbols for the units have their usual meaning: mg    (milligram); g (gram); ml (milliliter); ° C. (degree Celsius); mmol    (millimol); nmol (nanomol); cm (centimeter).-   (vi) The abbreviations have the following meaning: m.p. (melting    point); b.p. (boiling point).-   (vii) In the present application, the pressure values are given in    millibar; the expression “room temperature” is understood to mean a    temperature of between 20° C. and 25° C.

Example 1 Ethyl 3-cyclopenten-1-ylbenzoate (4a)

The following are successively introduced into a round-bottomed flask: 7g of ethyl 3-iodobenzoate (25 mmol), 11.2 ml of cyclopentene (127 mmol),21 ml of ethanol, 1.16 g of Pd₂ dba₃ complex (1.27 mmol), 8.8 g ofpotassium carbonate (63 mmol) and 8.17 g of nBu₄NBr (25 mmol). Themedium is heated at 80° C. for 16 hours and then the black mixture isfiltered on celite. The precipitate is washed with ethyl acetate. Thefiltrate is washed with water and then with a saturated aqueous sodiumchloride solution, dried over sodium sulfate, filtered and thenconcentrated under reduced pressure. The title product, which isisolated by bulb to bulb distillation (5.2 g), is obtained in the formof a pale yellow oil.

¹H NMR (CDCl₃): δ 1.39 (t, J=7.1 Hz, 3H); 2.04 (m, 2H); 2.54 (m, 2H);2.73 (m, 2H); 4.34 (q, J=7.1 Hz, 2H); 6.27 (s, 1H); 7.35 (t, J=7.7 Hz,1H); 7.61 (d, J=7.8 Hz, 1H); 7.88 (d, J=7.8 Hz, 1H); 8.06 (s, 1H).

Example 2 (3-Cyclopenten-1-ylphenyl)methanol (5a)

A solution of ethyl 3-cyclopent-1-ylbenzoate (4a) (2.5 g, 12 mmol) inether (25 ml) is added dropwise to a suspension at 0° C. of LiAlH₄ (0.57g, 15 mmol) in ethyl ether (30 ml). The mixture is stirred overnight atroom temperature. The reaction mixture is cooled to 0° C. and then 4.1ml of a 10% aqueous sodium hydroxide solution are added dropwise. Thewhite precipitate formed is filtered under vacuum, the solid washed withether and then the filtrate concentrated under reduced pressure. Theresidue is purified by flash chromatography on silica gel(cyclohexane/ethyl acetate: 90/10). The title product (1.35 g) isobtained in the form of a colorless oil.

¹H NMR (CDCl₃): δ 2.02 (m, 2H); 2.53 (m, 2H); 2.72 (m, 2H); 3.74 (s,1H); 4.68 (d, J=6.0 Hz, 2H); 6.21 (s, 1H); 7.20 (d, J=7.4 Hz, 1H); 7.29(t, J=7.6 Hz, 1H); 7.38 (d, J=7.7 Hz, 1H); 7.44 (s, 1H).

Example 3 3-Cyclopenten-1-ylbenzaldehyde (2a)

1.35 g (8 mmol) of (3-cyclopenten-1-ylphenyl)methanol (5a) and 80 ml ofchloroform are introduced into a round-bottomed flask. 6.8 g of MnO₂ arethen added and the suspension is heated at 60° C. for 2 hours. Themixture is filtered in the hot state, the precipitate washed withchloroform and then the filtrate concentrated under reduced pressure.The title product (1.05 g) is obtained in the form of a yellow oil whichis used in the next step without further purification.

¹H NMR (CDCl₃): δ 2.06 (m, 2H); 2.57 (m, 2H); 2.72 (m, 2H); 6.30 (s,1H); 7.49 (t, J=7.6 Hz, 1H); 7.71 (m, 2H); 7.91 (s, 1H); 10.02 (s, 1H)

Example 4 Ethyl 3-(6-oxabicyclo[3.1.0]hex-1-yl)-benzoate (6)

5 g (23 mmol) of ethyl 3-cyclopent-1-ylbenzoate (4a) and 100 ml ofmethylene chloride are introduced into a round-bottomed flask. Thesolution is cooled to 0° C. and 9 g (28 mmol) of meta-chloroperbenzoicacid are added in portions. The mixture is stirred for 30 minutes at 0°C. and then for 4 hours at room temperature. The mixture is filtered.The filtrate is successively washed with a saturated aqueous sodiumthiosulfate solution, a saturated aqueous sodium bicarbonate solutionand then with a saturated aqueous sodium chloride solution. The organicphase is dried over Na₂SO₄, filtered and concentrated under reducedpressure. The residue is purified by flash chromatography on silica gel(cyclohexane/ethyl acetate: 95:5). The title product is obtained in theform of a colorless oil (4.8 g).

¹H NMR (CDCl₃): δ 1.40 (t, J=7.2 Hz, 3H); 1.62 (m, 1H); 1.78 (m, 2H);2.13 (m, 1H); 2.24 (m, 2H); 3.57 (s, 1H); 4.38 (q, J=7.2 Hz, 2H); 7.41(t, J=7.7 Hz, 1H); 7.56 (d, J=7.7 Hz, 1H); 7.96 (d, J=7.7 Hz, 1H); 8.06(s, 1H).

Example 5 Ethyl 3-(2-oxocyclopentyl)benzoate (7)

4 g (17.2 mmol) of ethyl 3-(6-oxabicyclo[3.1.0]hex-1-yl)benzoate (6) and50 ml of methylene chloride are introduced into a round-bottomed flask.The mixture is cooled to 0° C. and then 2.2 ml (17.2 mmol) of BF₃.Et₂Oare added dropwise. The reaction mixture is stirred at 0° C. for 1 hourand then 25 ml of a saturated aqueous sodium bicarbonate solution areadded. The mixture is separated by settling and the aqueous phaseextracted with methylene chloride. The combined organic phases are driedover MgSO₄, filtered and concentrated under reduced pressure. Theresidue is purified by flash chromatography on silica gel(cyclohexane/ethyl acetate: 80/20). The title product is obtained in theform of a pale yellow oil (3.4 g).

¹H NMR (CDCl₃): δ 1.38 (t, J=7.2 Hz, 3H); 1.98 (m, 1H); 2.17 (m, 2H);2.31 (m, 1H); 2.51 (m, 2H); 3.38 (dd, J=11.2; 8.6 Hz, 1H); 4.36 (q,J=7.2 Hz, 2H); 7.39 (m, 2H); 7.86 (s, 1H), 7.93 (m, 1H).

Example 6 Alkyl 3-(2-fluorocyclopenten-1-yl)benzoate (4b)

4 g of ethyl 3-(2-oxocyclopentyl)benzoate (7) (17.2 mmol) and 8 ml oftoluene are added to a round-bottomed flask. 9 ml of DAST (69 mmol) arethen added dropwise and the mixture is heated at 60° C. for 16 hours.The solution is poured into an ice/sodium bicarbonate mixture and thenthe mixture is extracted with methylene chloride. The organic phase iswashed with water, with an aqueous saturated sodium chloride solution,dried over sodium sulfate, filtered and then concentrated under reducedpressure. The residue is purified by filtration on silica gel(cyclohexane/ethyl acetate: 90/10). The brown oil obtained (2.9 g) istaken up in tetrahydrofuran (50 ml) and the solution cooled to −15° C.34 ml of potassium tert-butoxide (1M in tetrahydrofuran, 34 mmol) areslowly added and the mixture is stirred at −15° C. for 3 hours. Themixture is poured into water, extracted with ether and then the combinedorganic phases are washed with a saturated aqueous sodium chloridesolution, dried over MgSO₄ and concentrated under reduced pressure. Abrown oil (2.5 g) is obtained which is used in the next step withoutfurther purification.

Example 7 3-(2-Fluorocyclopenten-1-yl)methanol (5b)

A solution of the derivative (4b) (2 g, 9 mmol) in ethyl ether is addeddropwise to a suspension of LiAlH₄ (0.8 g, 21 mmol) in ether (20 ml)kept at 0° C. The reaction mixture is slowly heated to room temperatureand then stirred for 16 hours. A 10% aqueous sodium hydroxide solution(4 ml) is then added at 0° C. The white precipitate formed is filteredunder vacuum, washed with ether and then the filtrate concentrated underreduced pressure. The residue is purified by flash chromatography onsilica gel (cyclohexane/ethyl acetate: 70/30). The title product isobtained in the form of a pale yellow oil (1.62 g).

¹H NMR (CDCl₃): δ 1.58 (s, 1H); 2.02 (m, 2H); 2.70 (m, 4H); 4.70 (s,2H); 7.23 (m, 1H); 7.34 (t, J=7.7 Hz, 1H); 7.39 (m, 1H); 7.45 (m, 1H).

Example 8 3-(2-Fluorocyclopenten-1-yl)benzaldehyde (2b)

A suspension of MnO₂ (1.6 g) and 3-(2-fluorocyclopenten-1-yl)methanol(5b) (0.64 g, 3.3 mmol) in 15 ml of chloroform is heated at 60° C. for 5hours. The mixture is filtered in the hot state, the precipitate iswashed with chloroform and then the filtrate concentrated under reducedpressure. The residue is purified by flash chromatography on silica gel(cyclohexane/ethyl acetate: 80/20). The title product is obtained in theform of a and a yellow oil is obtained (0.56 g).

¹H NMR (CDCl₃): δ 2.04 (m, 2H); 2.74 (m, 4H); 7.51 (t, J=7.7 Hz, 1H);7.73 (d, J=7.6 Hz, 1H); 7.93 (s, 1H); 7.79 (d, J=7.7 Hz, 1H); 10.02 (s,1H).

Example 9 1-(5-Bromopyridin-3-yl)cyclopentanol (8)

A few drops of 1,4-dibromobutane and 25 ml of tetrahydrofuran are addedto a round-bottomed flask containing 2.25 g of magnesium chips (92.6mmol) and an iodine crystal. The mixture is heated at 65° C. untildecolorization is obtained and then a solution of 1,4-dibromobutane (10g, 46.3 mmol) in 50 ml of tetrahydrofuran is added dropwise. Thereaction mixture is heated at 65° C. for 4 hours and then cooled to 0°C. A solution of ethyl 2-bromonicotinate (10 g, 46.3 mmol) in 60 ml oftetrahydrofuran is then added. The reaction mixture is cooled to roomtemperature and stirred for 16 hours. The reaction mixture is slowlypoured at 0° C. into a saturated aqueous ammonium chloride solution andthen the medium is extracted with ethyl acetate. The organic phase iswashed with water and then with a saturated aqueous sodium chloridesolution, dried over sodium sulfate, filtered and concentrated underreduced pressure. The residue is purified by flash chromatography onsilica gel (cyclohexane/ethyl acetate: 70/30). The title product (3.6 g)is obtained in the form of a white solid.

m.p.=74° C.

¹H NMR (CDCl₃): δ 1.76 (m, 2H); 1.87 (m, 6H); 2.73 (m, 2H); 3.93 (s,1H); 7.15 (d, J=5.0 Hz, 1H); 8.38 (d, J=5.0 Hz, 1H); 8.64 (s, 1H).

Example 10 3-Bromo-5-cyclopenten-1-ylpyridine (9)

A solution of 1-(5-bromopyridin-3-yl)cyclopentanol (8) (1.7 g, 11.3mmol) in 50 ml of toluene containing 5 ml of concentrated hydrochloricacid is heated at 120° C. for 12 hours with continuous carrying away ofthe water formed. The mixture is then poured into a saturated aqueoussodium bicarbonate solution and extracted with ethyl acetate. Thecombined organic phases are washed with water and then with a saturatedaqueous sodium chloride solution, dried over sodium sulfate, filteredand concentrated under reduced pressure. The residue is purified byflash chromatography on silica gel (cyclohexane/ethyl acetate: 60/40).The title product is obtained in the form of a beige solid (1.65 g).

m.p.=43° C.

¹H NMR (CDCl₃): δ 2.05 (m, 2H); 2.57 (m, 2H); 2.72 (m, 2H); 6.31 (s,1H); 7.82 (m, 1H); 8.49 (d, J=2.0 Hz, 1H); 8.59 (d, J=2.0 Hz, 1H)

Example 11 5-Cyclopenten-1-ylpyridine-3-carboxaldehyde (2c)

A solution of 3-bromo-5-cyclopenten-1-ylpyridine (9) (1 g, 4.5 mmol) in25 ml of ether is added to a solution of n-butyllithium (1.6M in hexane,4.2 ml, 6.7 mmol) in 25 ml of ether kept at −60° C. The reaction mixtureis stirred for 2 h 30 min at −60° C. and then 1.4 ml of4-morpholinecarboxaldehyde (13.4 mmol) are added. The reaction isstirred for 1 hour at −60° C. and then poured into water, the organicphase is washed with a saturated aqueous sodium chloride solution, driedover sodium sulfate, filtered and concentrated under reduced pressure.The residue is purified by flash chromatography on silica gel(cyclohexane/ethyl acetate: 80/20). The title product is obtained in theform of a beige solid (0.38 g).

m.p.=50° C.

¹H NMR (CDCl₃): δ 2.10 (m, 2H); 2.61 (m, 2H); 2.72 (m, 2H); 6.49 (s,1H); 8.32 (s, 1H); 8.89 (s, 1H); 8.93 (s, 1H); 10.10 (s, 1H).

Example 12 7-(tert-Butyldimethylsilanyloxy)benzofuran-2-methoxycarbonyl(13)

1.61 g of tert-butyldimethylsilane (10.7 mmol) and 0.73 g of imidazole(10.7 mmol) are added to a solution of7-hydroxybenzofuran-2-methoxycarbonyl (1.96 g, 10.2 mmol) indimethylformamide (10 ml), kept at 0° C. The mixture is stirred for 16hours at room temperature. The mixture is then poured into water,extracted with ethyl acetate and the combined organic phases are washedwith a saturated aqueous sodium chloride solution, dried over MgSO₄ andconcentrated under reduced pressure. The residue is purified by flashchromatography on silica gel (cyclohexane/ethyl acetate: 95/5). Thetitle product is obtained in the form of a pale yellow oil (3.1 g).

¹H NMR (CDCl₃): δ 0.27 (s, 6H); 1.05 (s, 9H); 3.95 (s, 3H); 6.92 (d,J=7.7 Hz, 1H); 7.14 (t, J=7.8 Hz, 1H); 7.25 (d, J=7.8 Hz, 1H); 7.49 (s,1H).

Example 13 [7-(tert-Butyldimethylsilanyloxy)benzofuran-2-yl]methanol(14)

A solution of LiAlH₄ (8.4 ml, 8.4 mmol) in ethyl ether (1.0M) is addeddropwise to a solution of7-(tert-butyldimethylsilanyloxy)benzofuran-2-methoxycarbonyl (13) (2.15g, 7 mmol) in ether (14 ml), kept at 0° C. The mixture is stirred for 18hours at room temperature and then cooled to 0° C. and treated dropwisewith a 10% aqueous sodium hydroxide solution (1.6 ml). The precipitateformed is filtered under vacuum and washed with ether. The filtrate isconcentrated under reduced pressure to give a colorless liquid (1.8 g)used in the next step without further purification.

¹H NMR (CDCl₃): δ 0.24 (s, 6H); 1.04 (s, 9H); 1.85 (t, J=6.4 Hz, 1H);4.76 (d, J=6.0 Hz, 2H); 6.64 (s, 1H); 6.76 (d, J=7.7 Hz, 1H); 7.04 (t,J=7.7 Hz, 1H); 7.14 (d, J=7.7 Hz, 1H).

Example 14 tert-Butyldimethyl-(2-chloromethylbenzo-furan-7-yloxy)silane(15)

2.5 g (9.5 mmol) of triphenylphosphine and 0.92 ml (9.5 mmol) of carbontetrachloride are added to a solution of[7-(tert-butyldimethylsilanyloxy)-benzofuran-2-yl]methanol (14) (1.78 g,6.4 mmol) in methylene chloride (9 ml), kept at 0° C. The reactionmixture is stirred at 0° C. for 1 hour and then the solvent isevaporated under reduced pressure. The residue is taken up in 30 ml ofcyclohexane and stirred for 1 hour. The precipitate formed is filteredand the filtrate concentrated. The residue is purified by flashchromatography on silica gel (cyclohexane/ethyl acetate: 95/5). Thetitle product is obtained in the form of a pale yellow liquid (1.5 g).

¹H NMR (CDCl₃): δ 0.25 (s, 6H); 1.04 (s, 9H); 4.70 (s, 2H); 6.70 (s,1H); 6.80 (d, J=7.5 Hz, 1H); 7.07 (t, J=7.7 Hz, 1H); 7.14 (d, J=7.7 Hz,1H).

Example 15tert-Butyldimethyl-(2-methylene-2,3-dihydro-benzofuran-7-yloxy)silane(16)

LiAlH₄ (1.0M in tetrahydrofuran, 4.5 ml, 4.5 mmol) is added dropwise toa suspension of CrCl₃ (1.4 g, 8.85 mmol) in tetrahydrofuran (10 ml),kept at 0° C. and the mixture is stirred for 15 minutes. The solution isthen diluted with dimethylformamide (18 ml) and isopropanol (1.35 ml).tert-Butyldimethyl-(2-chloro-methylbenzofuran-7-yloxy)silane (15) (1.05g, 3.54 mmol) in dimethylformamide (15 ml) is added to the solutionobtained, kept at 0° C. The mixture is stirred at room temperature for18 hours and then poured into water and extracted with pentane. Theorganic phase is dried over Na₂SO₄, filtered and concentrated underreduced pressure. A colorless liquid is obtained (0.78 g) which is usedin the next step without further purification.

¹H NMR (CDCl₃): δ 0.21 (s, 6H); 1.00 (s, 9H); 3.89 (s, 2H); 4.26 (d,J=2.0 Hz, 1H); 4.69 (d, J=2.0 Hz, 1H); 7.72 (m, 1H); 7.79 (m, 1H).

Example 16tert-Butyldimethyl-(2-spirocyclopropane-2,3-dihydrobenzofuran-7-yloxy)silane(17)

A solution of diethylzinc in toluene (1.1M, 6.8 ml, 7.48 mmol) is addedto a solution oftert-butyldimethyl-(2-methylene-2,3-dihydrobenzofuran-7-yloxy)silane(16) (0.78 g, 2.97 mmol) in dichloroethane (15 ml) kept at 0° C. Afterthe addition, 1.1 ml of chloroiodomethane (15 mmol) are added and themixture is stirred at 0° C. for 1 hour and then at 50° C. for 1.5 hours.The mixture is cooled to 0° C. and a saturated aqueous ammonium chloridesolution (10 ml) is added. After stirring for 15 minutes, the mixture isdiluted with methylene chloride, washed with water and then with asaturated aqueous sodium chloride solution. The organic phase is driedover Na₂SO₄, filtered and concentrated under reduced pressure. Theresidue is purified by flash chromatography on silica gel(cyclohexane/ethyl acetate: 98/2). The title product is obtained in theform of a colorless oil (0.75 g).

¹H NMR (CDCl₃): δ 0.15 (s, 6H); 0.67 (s, 2H); 0.96 (s, 9H); 1.16 (s,2H); 3.28 (s, 2H); 6.69 (m, 2H); 6.77 (m, 1H).

Example 17 2-Spirocyclopropane-2,3-dihydrobenzofuran-7-ol (10f)

A solution of tetrabutylammonium fluoride (1.0M in tetrahydrofuran, 3.1ml, 3.1 mmol) is added to a solution oftert-butyldimethyl-(2-spirocyclopropane-2,3-dihydro-benzofuran-7-yloxy)silane(17) (0.57 g, 2.06 mmol) in 10 ml of tetrahydrofuran at 0° C. Thesolution is stirred at 0° C. for 2 hours and then poured into water andextracted with ethyl acetate. The organic phase is washed with asaturated aqueous sodium chloride solution, dried over Na₂SO₄, filteredand concentrated under reduced pressure. The residue is purified byflash chromatography on silica gel (cyclohexane/ethyl acetate: 80/20).The title product (0.3 g) is obtained in the form of a white solid.

m.p.=85–86° C.;

¹H NMR (CDCl₃): δ 0.71 (t, J=6.4 Hz, 2H); 1.20 (t, J=6.4 Hz, 2H); 3.34(s, 2H); 4.77 (s, 1H); 6.76 (m, 3H).

Example 18[2-(2,2-Dimethyl-2,3-dihydrobenzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine(1a)

1.5 g of magnesium sulfate are added to a solution of3-cyclopenten-1-ylbenzaldehyde (2a) (0.56 g, 3.26 mmol) and of[2-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yl-oxy)]ethylamine (3a) (0.68g, 3.26 mmol) in 15 ml of 1,2-dichloroethane and the mixture is heatedat 60° C. for 17 hours. The mixture is cooled to room temperature, thesolid is filtered and the solvent is evaporated under reduced pressure.The residue is diluted with 15 ml of methanol and then cooled to 0° C.0.35 g of potassium borohydride (6.52 mmol) is then introduced and thereaction mixture is stirred for 3 hours at 0° C. The mixture is thenpoured into ice-cold water, extracted with ethyl acetate and washed witha saturated aqueous sodium chloride solution. The combined organicphases are dried over magnesium sulfate, filtered and the solvent isevaporated under reduced pressure. The residue is purified bychromatography on silica gel (methylene chloride/methanol/aqueousammonia: 98/1.5/0.5). The title product (0.61 g) is isolated in the formof a colorless oil.

¹H NMR (CDCl₃): δ 1.48 (s, 6H); 2.00 (m, 2H); 2.54 (m, 2H); 2.69 (m,2H); 3.01 (s, 2H); 3.04 (t, J=5.6 Hz, 2H); 3.85 (s, 2H); 4.18 (t, J=5.6Hz, 2H); 6.18 (s, 1H); 6.74 (m, 3H); 7.19 (d, J=7.4 Hz, 1H); 7.25 (t,J=8.7 Hz, 1H); 7.32 (d, J=7.6 Hz, 1H); 7.41 (s, 1H).

Fumarate of the title compound:

m.p.=146° C.

¹H NMR (DMSOd⁶): δ 1.39 (s, 6H); 1.96 (m, 2H); 2.51 (m, 2H); 2.65 (m,2H); 2.96 (t, J=5.6 Hz, 2H); 2.99 (s, 2H); 3.91 (s, 2H); 4.11 (t, J=5.6Hz, 2H); 6.27 (s, 1H); 6.56 (s, 2H); 6.71 (m, 1H); 6.79 (m, 2H); 7.31(m, 2H); 7.37 (d, J=7.6 Hz, 1H); 7.50 (s, 1H).

IR (KBr) ν: 3060, 2967, 1719, 1463 cm⁻¹;

Elemental analysis for C₂₄H₂₉NO₂.C₄H₄O₄ Theoretical %: C, 70.13; H,6.94; N, 2.92. Found: C, 69.92; H, 6.93; N, 2.89.

Example 19 [2-(Benzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine(1c)

By carrying out the procedure as in example 18, but using the2-(benzofuran-7-yloxy)ethylamine of formula (3c) in place of[2-(2,2-dimethyl-2,3-dihydrobenzo-furan-7-yloxy)]ethylamine of formula(3a), the title compound is obtained.

¹H NMR (CDCl₃): δ 2.04 (m, 2H); 2.53 (m, 2H); 2.70 (m, 2H); 3.12 (t,J=5.2 Hz, 2H); 3.90 (s, 2H); 4.33 (t, J=5.2 Hz, 2H); 6.19 (s, 1H); 6.76(s, 1H); 6.83 (d, J=7.6 Hz, 1H); 7.13 (t, J=7.8 Hz, 1H); 7.19 (m, 2H);7.29 (m, 2H); 7.33 (d, J=7.5 Hz, 1H); 7.44 (s, 1H); 7.61 (d, J=2.0 Hz,1H).

Fumarate of the title product:

m.p.=126° C.

¹H NMR (DMSOd⁶): δ 1.95 (m, 2H); 2.49 (m, 2H); 2.64 (m, 2H); 3.04 (t,J=5.6 Hz, 2H); 3.91 (s, 2H); 4.29 (t, J=5.6 Hz, 2H); 6.26 (s, 1H); 6.57(s, 2H); 6.93 (m, 2H); 7.15 (t, J=7.8 Hz, 1H); 7.26 (m, 3H); 7.36 (d,J=7.2 Hz, 1H); 7.49 (s, 1H); 7.95 (s, 1H);

IR (KBr) ν: 3498, 2952, 2842, 1701, 1486 cm⁻¹;

Elemental analysis for C₂₂H₂₃NO₂.C₄H₄O₄ Theoretical %: C, 69.47; H,6.05; N, 3.12 Found: C, 69.25; H, 6.08; N, 3.05.

Example 20[2-(2-Methylbenzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine(1d)

By carrying out the procedure as in example 18, but using the2-(2-methylbenzofuran-7-yloxy)ethylamine of formula (3d) in place of[2-(2,2-dimethyl-2,3-dihydro-benzofuran-7-yloxy)]ethylamine of formula(3a), the title compound is obtained.

¹H NMR (CDCl₃): δ 2.01 (m, 2H); 2.45 (s, 3H); 2.53 (m, 2H); 2.71 (m,2H); 3.12 (t, J=5.6 Hz, 2H); 3.89 (s, 2H); 4.32 (t, J=5.6 Hz, 2H); 6.20(s, 1H); 6.36 (s, 1H); 6.76 (m, 1H); 7.07 (m, 2H); 7.21 (d, J=7.4 Hz,1H); 7.28 (m, 2H); 7.33 (d, J=7.6 Hz, 1H); 7.43 (s, 1H).

Fumarate of the title product:

m.p.=133° C.

¹H NMR (DMSOd⁶): δ 1.96 (m, 2H); 2.43 (s, 3H); 2.49 (m, 2H); 2.67 (m,2H); 3.02 (t, J=5.6 Hz, 2H); 3.89 (s, 2H); 4.26 (t, J=5.6 Hz, 2H); 6.26(s, 1H); 6.55 (s, 1H); 6.57 (s, 2H); 6.84 (m, 1H); 7.08 (m, 2H); 7.28(m, 2H); 7.35 (d, J=7.3 Hz, 1H); 7.49 (s, 1H);

IR (KBr) ν: 3421, 3048, 2952, 2846, 1709, 1587 cm⁻¹;

Elemental analysis for C₂₃H₂₅NO₂.C₄H₄O₄ Theoretical %: C, 69.96; H,6.31; N, 3.02 Found: C, 70.04; H, 6.30; N, 2.98.

Example 21[2-(2,3-Dihydrobenzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine(1e)

By carrying out the procedure as in example 18, but using the2-(2,3-dihydrobenzofuran-7-yloxy)ethylamine of formula (3e) in place of[2-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)]ethylamine of formula(3a), the title compound is obtained.

¹H NMR (DMSOd⁶): δ 1.95 (m, 2H); 2.40 (m, 2H); 2.65 (m, 2H); 2.81 (t,J=5.6 Hz, 2H); 3.13 (t, J=8.8 Hz, 2H); 3.74 (s, 2H); 4.03 (t, J=5.6 Hz,2H); 4.46 (t, J=8.8 Hz, 2H); 6.25 (s, 1H); 6.79 (m, 3H); 7.27 (m, 3H);7.42 (s, 1H).

Fumarate of the title product:

m.p.=118° C.

¹H NMR (DMSOd⁶): δ 1.92 (m, 2H); 2.49 (m, 2H); 2.65 (m, 2H); 2.93 (t,J=5.6 Hz, 2H); 3.16 (t, J=8.8 Hz, 2H); 3.88 (s, 2H); 4.11 (t, J=5.6 Hz,2H); 4.50 (t, J=8.8 Hz, 2H); 6.27 (s, 1H); 6.56 (s, 2H); 6.81 (m, 3H);7.24 (d, J=6.9 Hz, 1H); 7.30 (t, J=7.4 Hz, 1H); 7.36 (d, J=7.3 Hz, 1H);7.48 (s, 1H);

IR (KBr) ν: 3536, 3448, 2949, 2851, 1612, 1466 cm⁻¹;

Elemental analysis for C₂₂H₂₅NO₂.C₄H₄O₄ Theoretical %: C, 69.16; H,6.47; N, 3.10 Found: C, 68.99; H, 6.55; N, 3.32.

Example 22[2-(2-Spirocyclopropyl-2,3-dihydrobenzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine(1f)

By carrying out the procedure as in example 18, but using the2-(2-spirocyclopropyl-2,3-dihydrobenzofuran-7-yloxy)ethylamine offormula (3f) in place of[2-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)]ethylamine of formula(3a), the title compound is obtained.

¹H NMR (CDCl₃): δ 0.69 (t, J=6.4 Hz, 2H); 1.22 (t, J=6.4 Hz, 2H); 1.23(s, 1H); 2.01 (m, 2H); 2.51 (m, 2H); 2.70 (m, 2H); 3.01 (t, J=5.2 Hz,2H); 3.31 (s, 2H); 3.84 (s, 2H); 4.17 (t, J=5.2 Hz, 2H); 6.18 (s, 1H);6.83 (m, 3H); 7.18 (d, J=7.4 Hz, 1H); 7.25 (t, J=7.6 Hz, 1H); 7.31 (d,J=7.6 Hz, 1H); 7.40 (s, 1H).

Maleate of the title product:

m.p.=180° C.

¹H NMR (DMSOd⁶): δ 0.78 (t, J=6.4 Hz, 2H); 1.06 (t, J=6.4 Hz, 2H); 1.98(m, 2H); 2.51 (m, 2H); 2.67 (m, 2H); 3.32 (m, 4H); 4.23 (m, 4H); 6.02(s, 2H); 6.32 (s, 1H); 6.83 (m, 3H); 7.38 (m, 2H); 7.51 (d, J=7.6 Hz,1H);

IR (KBr) ν: 3454, 2998, 2957, 2841, 1621, 1461 cm⁻¹;

Elemental analysis for C₂₄H₂₇NO₂.C₄H₄O₄ Theoretical %: C, 70.42; H,6.54; N, 2.93 Found: C, 70.27; H, 6.59; N, 3.14.

Example 23[2-(2,2-Dimethyl-2,3-dihydrobenzofuran-7-yl-oxy)ethyl]-[3-(2-fluorocyclopenten-1-yl)benzyl]amine(1 g)

By carrying out the procedure as in example 18, but using3-(2-fluorocyclopenten-1-yl)benzaldehyde of formula (2b) in place of the3-cyclopenten-1-ylbenzaldehyde of formula (2a), the title compound isobtained.

¹H NMR (CDCl₃): δ 1.48 (s, 6H); 1.97 (s, 1H); 2.01 (m, 2H); 2.68 (m,4H); 3.00 (s, 2H); 3.03 (t, J=5.2 Hz, 2H); 3.86 (s, 2H); 4.19 (t, J=5.2Hz, 2H); 6.78 (m, 3H); 7.21 (d, J=7.5 Hz, 1H); 7.29 (t, J=7.6 Hz, 1H);7.41 (d, J=7.6 Hz, 1H); 7.44 (s, 1H)

Fumarate of the title product:

m.p.=145° C.

¹H NMR (DMSOd⁶): δ 1.39 (s, 6H); 1.95 (m, 2H); 2.67 (m, 4H); 2.94 (t,J=5.6 Hz, 2H); 3.03 (s, 2H); 3.87 (s, 2H); 4.09 (t, J=5.6 Hz, 2H); 6.57(s, 2H); 6.72 (m, 1H); 6.79 (m, 2H); 7.27 (d, J=7.5 Hz, 1H); 7.34 (m,2H); 7.47 (s, 1H);

IR (KBr) ν: 3426, 2962, 1675, 1463 cm⁻¹;

Elemental analysis for C₂₄H₂₈NFO₂.C₄H₄O₄ Theoretical %: C, 67.59; H,6.48; N, 2.82 Found: C, 67.44; H, 6.59; N, 2.88.

Example 24[2-(2,2-Dimethyl-2,3-dihydrobenzofuran-7-yl-oxy)ethyl]-(5-cyclopenten-1-ylpyridin-3-ylmethyl)amine(1b)

By carrying out the procedure as in example 18, but using5-cyclopenten-1-ylpyridin-3-ylcarboxaldehyde of formula (2c) in place ofthe 3-cyclopenten-1-ylbenzaldehyde of formula (2a), the title compoundis obtained.

¹H NMR (CDCl₃): δ 1.74 (s, 6H); 2.06 (m, 2H); 2.54 (m, 2H); 2.70 (m,2H); 3.01 (m, 4H); 3.86 (s, 2H); 4.19 (t, J=5.2 Hz, 2H); 6.28 (s, 1H);6.75 (m, 3H); 7.71 (s, 1H); 8.49 (s, 1H); 8.57 (s, 1H).

Fumarate of the title product:

m.p.=141° C.

¹H NMR (DMSOd⁶): δ 1.39 (s, 6H); 1.98 (m, 2H); 2.51 (m, 2H); 2.69 (m,2H); 2.92 (t, J=5.6 Hz, 2H); 2.98 (s, 2H); 3.89 (s, 2H); 4.08 (t, J=5.6Hz, 2H); 6.42 (s, 1H); 6.59 (s, 2H); 6.71 (m, 1H); 6.78 (m, 2H); 7.84(s, 1H); 8.50 (s, 1H); 8.59 (s, 1H);

IR (KBr) ν: 3036, 2973, 2847, 1715, 1618, 1491 cm⁻¹;

Elemental analysis for C₂₃H₂₈N₂O₂.C₄H₄O₄

Theoretical %: C 67.48 H 6.71 N 5.83 Found: C 67.14 H 6.72 N 5.79.

Pharmacological study of the compounds of the invention.

1—Measurement of the affinity of the compounds of the invention for theD₂ receptors.

The affinity in vitro of the compounds of the invention for thereceptors of the D₂ type was determined by measuring the displacement of(³H) YM-09151-2 (NET-1004 70-87 Ci/mmol) according to the methoddescribed in Naunyn-Schimiedeberg's Arch. Pharmacol. Methods, 1985, 329,333. The pKi values, (pKi=−log Ki), are given in the form of themean±SEM of at least 3 experiments.

2—Measurement of the affinity of the compounds of the invention for the5-HT1_(A) receptors.

The affinity in vitro of the compounds of the invention for thereceptors of the 5-HT_(1A) subtype was determined by measuring thedisplacement of [³H]8-OH-DPAT (TRK 850; 160-240 Ci/mmol). The study ofthe binding to the 5-HT_(1A) receptor is carried out as described bySleight and Peroutka (Naunyn-Schimiedeberg's Arch. Pharmaco. 1991, 343,106).

The pKi values, (pKi =−log Ki), are given in the form of the mean±SEM ofat least 3 experiments.

3—Evaluation of the antagonist activity of the D₂ receptors in vivo.

The test demonstrating the antidopaminergic activity in vivo of thecompounds of the invention is based on the inhibition of the behaviorinduced by methylphenidate, measured in rats, according to the methoddescribed in J. Pharmacol. Exp. Ther. 1993, 267, 181.

4—Evaluation of the cataleptigenic effects of the compounds of theinvention.

The test which makes it possible to evaluate the propensity of theproducts of the invention to cause side effects of an extrapyramidalnature is based on their cataleptigenic power, measured in rats,according to the method described in Eur. J. Pharmacol, 1996, 313, 25.

The table below gives, by way of example, the pKi values, measured onthe D₂ and 5-HT1_(A) receptors, and the effective doses (ED₅₀) obtainedafter administration of certain products of the invention by the oralroute in animals. The properties of the compounds of the invention arecompared with those of substances chosen as reference which are used inhuman clinical medicine, i.e. nemonapride (mixed compound: D₂ antagonistand 5-HT1_(A) agonist), risperidone (atypical antipsychotic) andhaloperidol (conventional antipsychotic).

TABLE D₂ 5-HT1_(A) Normalization Catalepsy Compound pKi pKi ED₅₀ mg/kgED₅₀ mg/kg 1a 9.5 8.2 1.3 >40 1f 9.2 8.2 0.63 >40 nemonapride 9.9 8.41.5 5.0 Risperidone 8.7 6.0 6.5 3.5 haloperidol 9.0 5.8 0.46 0.92

It is evident from this study that the compounds of the inventionpossess a high affinity for the receptors of the D₂ and 5-HT1_(A)subtypes. The ratio of the pKi values, which is practically identicalfor the compounds of the invention and nemonapride[pKi(D₂)/pKi(%-HT1_(A))≅1.3], shows that the compounds of the inventionand nemonapride have comparable affinity profiles (D₂ and 5-HT1_(A)).Risperidone and haloperidol possess, for their part, a good affinity forthe D₂ receptors, but exhibit only a low affinity for the 5-HT1_(A)receptors.

The antidopaminergic activities in vivo of the products of the inventionand those of the reference compounds are expressed in relativelycomparable dose ranges. On the basis of the criterion for normalizationof the stereotypisms, the contribution made by a 5-HT1_(A) activationtherefore does not appear in a striking manner. However, we observe thatamong the compounds of the study, the products having a high affinityfor the 5-HT1_(A) receptors (i.e. 1a, 1f and nemonapride) have a lowerpropensity to cause catalepsy. This tendency is clearly illustrated bythe comparison of the ratios of the cataleptigenic doses (undesirableeffect) and those necessary to normalize behavior (desiredpharmacological activity); thus, ED₅₀(catalepsy)/ED₅₀(normalization)>1in the case of the products 1a, 1f and nemonapride whereasED₅₀(catalepsy)/ED₅₀(normalization)<1 in the case of risperidone andhaloperidol. On the basis of the results for catalepsy which areobtained with nemonapride (ED₅₀=5 mg/kg), it is surprising that thecompounds of the invention (i.e. 1a and 1f) are, for their part, free ofany cataleptigenic effects, even in high doses (i.e. 40 mg/kg). It isonce again advantageous to compare theED₅₀(catalepsy)/ED₅₀(normalization) ratios; thus, whereas this ratio isapproximately equal to 3 in the case of nemonapride, it becomes greaterthan 30 for compounds 1a and 1f. It therefore appears obvious that:

-   -   the antidopaminergic and serotoninergic activities of the        compounds of the invention are both expressed in vivo in the        dose ranges tested;    -   the activities in question cooperate such that their combination        confers a significant advantage on the compounds of the        invention not only with respect to the products whose mechanism        of action is a priori similar (e.g. nemonapride) but also in        relation to the atypical antipsychotics (e.g. risperidone) and        conventional antipsychotics (e.g. haloperidol).

The compounds of the invention which are capable of behaving as potentand effective dopaminergic antagonists without however causing the sideeffects characteristic of the dopaminergic antagonists (i.e. catalepsyin animals), even at doses much higher than the pharmacological doses,are thereby potentially useful in the treatment of disorders in which adopaminergic dysfunction is involved, in particular schizophrenicpsychoses.

The administration of the compounds of the invention may be carried outorally, nasally, sublingually, rectally or parenterally. By way ofnonlimiting examples of formulation, a preparation of the compounds ofthe invention is given below. The ingredients and others which aretherapeutically acceptable may be introduced in other proportionswithout modifying the scope of the invention. The terms “activeingredient” used in the example of formulation below refer to a compoundof formula (1) or an addition salt or optionally a hydrate of anaddition salt of the compound of formula (1) with a pharmaceuticallyacceptable inorganic acid or organic acid.

Example of Pharmaceutical Composition

Preparation formula for 1000 tablets each containing 10 mg of activeingredient:

Active ingredient 10 g Lactose 100 g Wheat starch 10 g Magnesiumstearate 3 g Talc 3 g

1. A compound having the formula (1)

in which: (a) represents a single bond or a double bond; W represents aCH, CH₂, CHCH₃, CCH₃ or C(CH₃)₂ group, a C(CH₂)₂ group (i.e. a carbonatom bearing two methylene groups linked together so as to form aspiro-cyclopropane unit) or a C(CH₂)₃ group (i.e. a carbon atom bearingtwo methylene groups linked to another methylene group so as to form aspiro-cyclobutane unit) with the proviso, however, that when (a) is adouble bond, then W exclusively represents a OH or CCH₃ group, and thatwhen (a) is a single bond, then W exclusively represents a CH₂, CHCH₃,C(CH₃)₂, C(CH₂)₂ or C(CH₂)₃ group; X is a carbon atom bearing a hydrogenatom (CH); and Y is a hydrogen atom or a fluorine atom; or an additionsalt or hydrate thereof with a pharmaceutically acceptable inorganicacid or organic acid or a tautomeric form, pure enantiomer or mixture ofracemic or nonracemic enantiomers thereof.
 2. A compound as claimed inclaim 1, which is:[2-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine;[2-(benzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine;[2-(2-methylbenzofuran-7-yloxy)ethyl]-(3-cyclopenten-1 -ylbenzyl)amine;[2-(2,3-dihydrobenzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine;[2-(2-spirocyclopropyl-2,3-dihydrobenzofuran-7-yloxy)ethyl]-(3-cyclopenten-1-ylbenzyl)amine;or[2-(2,2-dimethyl-2,3-dihydrobenzofuran-7-yloxy)ethyl]-[3-(2-fluorocyclopenten-1-yl)benzyl]amine; or an addition salt or hydrate of said addition saltwith a pharmaceutically acceptable inorganic acid or organic acid or anisomer or tautomer thereof.
 3. A pharmaceutical composition comprising,as active ingredient, at least one compound as claimed in claim 1 and aninert pharmaceutical carrier or other pharmaceutically acceptablevehicle.
 4. A method for the treatment of schizophrenia comprisingadministering to an animal in need of such treatment an effectiveanti-psychotic amount of a composition as claimed in claim
 3. 5. Apharmaceutical composition comprising, as active ingredient, at leastone compound as claimed in claim 2 and an inert pharmaceutical carrieror other pharmaceutically acceptable vehicle.
 6. A method for thetreatment of schizophrenia comprising administering to an animal in needof such treatment an effective anti-psychotic amount of a composition asclaimed in claim
 5. 7. A process for the preparation of a compoundhaving the formula (1) as claimed in claim 1, said process comprisingreacting a compound having the formula (3) with a compound having theformula (2) according to the reaction scheme:

in which (a), W, X and Y are as defined in claim 1.